This invention relates to a control for a humidifier which is selectively operated to control the moisture in an air movement system in response to sensed electrical energy supplied to the air movement system.
Controls for air humidifiers have been designed to energize both a blower motor which conducts air through a circulating system and a humidifier which controls the moisture in the circulated air, such as illustrated in U.S. Pat. No. 3,840,001, which permits the blower to run for a period of time after the humidifier is shut off.
Various systems have sensed the current flow between a power source and a furnace blower for controlling the operation of a humidifier. On such system generally requires the severing of one or more connecting leads to directly electrically connect a primary of a sensing transformer having a secondary connected to operate a solenoid operated electro-mechanical switch having switching contacts for energizing the humidifier in response to the energization of the blower. When such blower motors are employed at higher operating speeds such as in conjunction with air conditioners, current transients are frequently encountered which may burn out or destroy such a sensing transformer.
Other systems have coiled one of the blower motor leads about an iron core associated with a current sensing coil to operatively energize and electro-magnetic relay to operate normally open contacts for energizing the humidifier.
Such prior systems which have slaved the humidifier operation to the operation of the blower have either interrupted or disfigured the blower lead being sensed and employ electro-mechanical relays which are subject to contact bounce and possible spurious operation due to external energy transients.